1. Field of the Invention
The present invention is directed to a strip of collated fasteners for a fastener driving tool.
The present invention is also directed to the exhaustion of debris from a nosepiece of the fastener driving tool.
2. Description of the Related Art
Fastener driving tools, such as combustion powered or explosive powder actuated tools are widely used for driving fasteners into substrates. Such fasteners include drive pins and nails designed to be forcibly driven into construction materials.
Fastener driving tools may use strips of collated fasteners for quick and easy feeding of fasteners to the tool. Usually, these strips are formed from a molded polymeric material with individual sleeves, bushings or holders for each of the fasteners to be collated. In most of these collation strips fillers are included to make the plastic easier to break away from the fastener when the fastener is driven by the tool. Each sleeve may have at least one frangible bridge between its neighboring sleeves to allow each sleeve to part or break away from the carrier easily. Commonly assigned U.S. Pat. No. 5,069,340 to Ernst et al. and U.S. Pat. Nos. 5,836,732 and 5,931,622 to Gupta et al., the disclosures of which are incorporated herein by reference, teach strips of collated fasteners in a set of sleeves having a portion that breaks away as the fastener is driven.
For applications such as the attachment of sheathing, such as gypsum board or plywood, to support studs it is desirable for the fastener head to be flush with the surface of the sheathing and for no residual plastic material from the collation strip to be present. As described above, many collation strips have been designed using polymeric plastics including fillers, such as talc or calcium carbonate, to cause the collation to be more brittle and break away from the fasteners easier. However, fillers can make the collation too brittle and can create problems. For example, some collation strips have been known to break in cold weather simply by dropping the collation strips. Also, many tools using the collation strips described above include a spring biased magazine follower within the magazine to push the collation toward the nosepiece of the tool. In some cases, the magazine follower has been known to break off pieces of the collation strip within the magazine, which jams the tool. Also, collation strips formed out of plastics including fillers have been know to shatter into small and irregular pieces, making clean-up of the spent sleeves difficult on the work site.
Another problem that can occur for exterior sheathing applications occurs when the sleeves do not completely break away from the fastener after the fastener has been driven into the substrate. This problem, commonly referred to as “flagging,” happens when a portion of the sleeve of the collation strip becomes trapped between the head of the fastener and the surface of the sheathing. Not only can flagging cause plastic to extend away from the surface of the sheathing but it can also cause the fastener head to stand off from the surface of the sheathing, both of which are undesirable because exterior sheathing is one of the final steps in construction, and appearance is important.
Still another problem that is known using collation strips is the ejections of the broken pieces of the sleeve as the fastener is being driven. Many tools used for driving fasteners into substrates create a large amount of force. This force is transferred to the fastener so that it is driven into the substrate, but it is also transferred from the fastener to the sleeve as the fastener breaks the sleeve apart. Broken pieces of sleeves sometimes have ejected away from the nosepiece at high speeds and in various directions.
What is needed is a collation strip of fasteners for a fastener driving tool where each sleeve breaks away cleanly from the rest of the collated strip, completely breaks away from the fastener being driven, and breaks into large pieces instead of shattering into many small pieces in order to avoid jamming of the fastener driving tool.
What is also needed is a mechanism on the fastener driving tool for easily and safely exhausting collation debris from the nosepiece of the tool.